Preamble Hello. Playoffs are usually about contrived drama, yet tonight's match between Udinese and Arsenal has the whiff of authenticity: it takes us back to the good old days of European competition, when an unseeded knockout meant there was no safety net for the big sides and they could go out of Europe before the advent calendars were off the production line, never mind in the shops. Admittedly this isn't an unseeded knockout; the authenticity is a contrived attempt by Uefa to replace some of the authenticity that was lost because of an earlier contrivance, but the results are exciting so we're not going to complain.

Tonight Arsenal are in serious danger of suffering a fate even worse than going out of Europe: being dumped into the Europa League. It's all gone wrong for them in the last couple of weeks. They have a number of injuries, Samir Nasri has done one, the sky is falling in on Arsene Wenger, and some of their supporters can't find any foie gras in the Islington M&S. These points will concern Arsenal fans, but they should also stimulate them. If they get through tonight it will feel approximately 47 billion times better than it would had they eased past the champions of San Marino, and the lack of foie gras allows you to buy some corned beef and roll back the years.

There is also the fact that tipping points are generally made of adversity, particularly for Wenger's Arsenal. In 1997-98 a dismal December run of four defeats in six games sparked an unbeaten surge to the title; in 2001-02 an unlucky defeat at home to Newcastle was followed by the early dismissal of Gio van Bronckhorst at Anfield in the next match. Arsenal won 2-1, thrillingly, and weren't beaten again in the league all season; in 2003-04, a tricky midweek tie against Italian opposition was followed by a trip to Old Trafford, Arsenal apparently fit for a mauling. Ruud van Nistelrooy missed a last-minute penalty, Arsenal manhandled him and used the fallout to foster a siege mentality that ultimately rendered them invincible.

Such a scenario is improbable this season, because Arsenal are a bit of a mess and Wenger, in essence a good man in a sport full of bad men, looks extremely tired. Yet it's far from impossible. Ultimately nobody knows anything, and at the very least Wenger deserves to be treated with far more respect than is currently the case, even if Arsenal do go out tonight.

They have generally had a great time of things in Italy, from the tragic Paul Vaessen's winner against Juventus to Thierry Henry shredding Roma and Inter. Even when Arsenal lose in Italy, they often win – second-leg defeats to Sampdoria in 1995 and Roma in 2009 were followed by victorious penalty shoot-outs. A similar scenario is conceivable here, although Arsenal will have to play well to get even that far. For them, this is a proper test. Just as European football should be.

Every loser wins, said 1980s visionary Nick Berry. And that might be the case tonight. Fenerbahce have been booted out of the Champions League because their hospitality buffets only stretch to 14 courses, not the 16 demanded by Uefa, and that means there is a spare place in this year's tournament. It has been suggested it may go to the play-off losers with the highest coefficient (Arsenal are second on that list behind Bayern Munich, who are already through), although this has not been confirmed by any of our snouts.

"How are you brother?"Is this modern football? Really? I was going to say that Garry Cook needs to take a long look in the mirror, but I suspect such an activity is the problem here rather than the solution.

Arf! "Is there any truth to the rumour that if Arsenal go thru that Liverpool, because of their high Uefa coefficient, could appear in the Champions League group stages?" asks Jesse Chula.

1 min Udinese kick off from right to left, and within 13 seconds Isla blasts a dangerous ball across the face of goal.

1 min Gervinho skins Ekstrand easily on the left and plays a dangerous ball across the face of the six-yard box that is claimed by the keeper Handanovic just ahead of the lurking Van Persie.

2 min It's been an electric start, and now Walcott's wobbling 20-yard shot is beaten away by Handanovic, who tumbled to his left and then had to move his hands back to the right.

3 min Five of the Arsenal players are 21 or under. You can't win anything with kids.

5 min It has been a refreshingly open start, from both sides. Agyemang-Badu runs 20 yards to within shooting range and then scuffs a left-footed shot straight at Szczesny from 20 yards.

6 min "Totally with you on the issue of the knock-out nature of this stage of Big Cup," says Mike Wilner. "Yesterday's games were fantastic – lots of goals and teams playing up-tempo football. It seems that the two-legged qualifiers are more exciting than the cagey knock-out matches in the later rounds. Got a reason for that?" Not really. It's cup football as nature intended I suppose.

8 min "So Arsenal could get eliminated today by Udinese, then get recalled into the tournament by Uefa, only to suffer the pain of being eliminated again in the group stages," says James Colern. "Come on, I can not be the only one in the world rubbing his hands with glee over this thought and seeing Wenger's reaction to it all."

9 min Di Natale has a goal disallowed for offside. It was a lovely volley on the turn from 10 yards, low into the corner, but he was definitely offside. Moments later, Gervinho's shot from 20 yards is straight at the keeper. This has been a storming start, with a retro feel to the game.

10 min Another half chance for Gervinho, who works the keeper Handanovic from a prohibitively tight angle on the right of the box. This is really good stuff, played at a furious pace - although the brutal humidity tonight means that this pace cannot last.

11 min "With LFC starting Suarez, Carragher, Reina, Adam and Henderson," begins Stephen Alexander, "it could be argued they have a stronger side appearing at their tricky away trip to Exeter City than Arsenal do at this ho-hum trip to Udinese." It could indeed. It could also be argued that chocolate is a cyborg, and that a diet of 474 fags an hour is better for you than pasta.

12 min A quiet 90 seconds. I want my money back.

14 min This Frimpong is going to be a player, isn't he. He has been very good so far.

17 min The first big chance of the match falls to Udinese. Di Natale dinks over a dangerous cross from the right of the box that is headed down, back whence it came, by Armero. It's bobbling towards the far post when Asamoah, from an offside position, studs it against that post, and the flag goes up. Had it gone straight in the goal would have been given, although I think it was going to hit the post anyway.

20 min A fibrous surge from Agyemang-Badu ends with Di Natale working Szczesny with a good low strike from 20 yards. It was a comfortable, tumbling save in the end. "Given this game's storming start, would it be a dereliction of footballing duty for me to turn off ITV in favour of the Komodo Dragon programme just starting on BBC2?" says Ryan Dunne. "What would Gunnersaurus Rex do? They have poisonous bites, can run fast as dogs and can clime trees you know (Komodo Dragons, not mascots)." But do they have Peter Drury commentating?

23 min Di Natale hits the post! It was a lovely, incisive move from Udinese. The dominant Ageymang-Badu seized upon a clearing header from Sagna, surged forward and found Isla on the right of the box. He passed the ball first time towards Di Natale at the near post, and he got in front of Djourou before clipping the ball off the face of the near post of his six yards. It was in no way a bad miss, but a finisher of his quality will probably feel he should have scored.

24 min Udinese are starting to dominate this match.

25 min "I haven't seen you mention him yet," says Stephen Alexander. "Is he walking around bored or confused? Is he aware of the game being played around him?" He's on the bench.

27 min Frimpong puts in a zesty one on Asamoah, who was breaking towards the halfway line. He would probably have been booked for that in the Premier League, but European referees tend to be a little calmer.

28 min This is an excellent and enjoyable game of football. That's all.

29 min Apparently the humidity is particularly severe in Udine, so this could be a magnificent farce if it goes to extra time. A lovely run from Asamoah is ended by a wonderfully decisive challenge from Frimpong on the edge of the area.

30 min A disgusting defensive header from Neuton, the sort that should bring a custodial sentence, comes straight to Van Persie in space on the edge of the area. He takes a touch and then slaps a poor right-footed shot miles over the bar.

31 min The humidity, by all accounts (well, Peter Drury on ITV), is going to be a huge factor in this game. Extra time could be a total farce, if we go that far.

32 min "Arsenal have to win to go through. Trabzonspor have replaced Fenerbahce in the group stage, FYI," says David Sterling, politely doing my job for me.

33 min A wonderful double save from Handanovic. Gervinho broke down the left of the box, came back inside cleverly and laid it square lovingly to Walcott, ten yards from goal and in space because all the defenders were running the other way. Handanovic roared from his line to block Walcott's sidefoot, and then got to his feet to block Van Persie's follow up. Udinese break and, within 10 seconds, Di Natale shoots from a very tight angle and forces a decent save from Szczesny. This is terrific stuff.

35 min "Some consistency please!" says Spencer Jones. "Last season all we heard was how Bob Mancini only signed defensive midfielders (Barry, Kompany, De Jong, Yaya, Viera) so he could put out a 9-0-1, and now they are actively avoided?" Apologies. I won't do a joke again.

36 min Udinese win a corner, their first of the match I think. It's clipped towards the near post, flicked on dangerously by Steve Bould Benatia, and headed clear at the far post by Vermaelen.

37 min Frimpong was scheduled for last year's first team before his injury," says Patrick Groden. "And it's likely that he'll be better in a year when his recovery is complete. As you may have noticed with Anderson, the return to top form from cruciate-ligament injuries takes time. Frimpong's lost season stands mute against of the barrage of "Wenger's too [fill in your adjectives here] to buy", "Arsenal need [more adjectives here] in midfield" bleating. Wenger actually does know something about the young players he's trying to bring through. At this rate though they may end up run down like Wilshere was last year. The workload is the only part of the "man's game" cliche that has any real truth to it."

39 min A good spell of possession from Arsenal, 90 seconds or so. They needed that as the game was a little too scattered for comfort. Gervinho eventually gives the ball away to Isla, who tries to go long to Di Natale. He fails to control an awkward ball and we're back where we started, with Arsenal in possession.

GOAL! Udinese 1-0 Arsenal (Di Natale 39) What a goal. What a lovely goalscorer's goal from Antonio Di Natale. Pinzi picked up the ball 35 yards from goal, in a central position, and lifted an angled reverse pass towards Di Natale, who had backpedalled instinctively away from Djourou. He was 15 yards from goal, with no pace in his body or on the ball to work with, but he strained his neck muscles to place a looping header over Szczesny and in off the far post. There will be many more eye-catching goals this season, but there will be few more accomplished finishes. Gerd Muller would have been proud of that.

42 min Arsenal need half time, big time.

43 min Another dangerous low cross from the impressive Isla on the right is half cleared by Djourou and spanked over from the edge of the box by the onrushing Armero. He might have done better there. Arsenal really, really, really need half time now.

44 min "I thought Uefa were clamping down on this 'football' business?" says Stuart Chapman. "We're in danger of an exciting game breaking out here."

45 min Walcott wins Arsenal a corner on the right. Van Persie booms it way beyond the far post, and Song heads wide. That should be it for the half.

Half time: Udinese 1-0 Arsenal An excellent half of retro football. What more do you want, a precis? Oh.

Half-time chit-chat "When Di Natale is mentioned his name makes me think of a pregnant man," chirps Ian Copestake. "Can you reassure me he is not stopping every two minutes to hold his back?"

The last time Arsenal failed to reach the group stages of the Champions League was 1997-98. If they lose here that will be used to damn him, when really it should be used to defend him. He has given the club an equilibrium that was unimaginable before he arrived. Arsenal have finished in the top four in each of the last 15 seasons; before that their best run was five years in a row.

46 min Arsenal kick off from right to left. Tomas Rosicky has come on for Emmanuel Frimpong, which is a slight surprise I suppose.

47 min "It certainly was a lovely goal but what specifically is a 'goalscorer's goal'?" says Alan Boardman. "Di Natale is a goalscorer and he did score a goal, and it is important for the goalscorer to score the goal otherwise it would never be considered a goalscorer's goal even if the goal was scored by the goalkeeper, he would still be the goalscorer, as a goal is almost always considered scored. except in the event of an own goal - when the goalscorer is an idiot!" Yes, very good. It was the sort of goal only a natural goalscorer would score, in terms of the awareness, the reaction speed, the imagination and the precision of the finish. Something like that anyway. I'm just typing any old nonsense and hoping some of it sticks.

48 min That substitution is a very positive one from Arsenal. Ramsey has dropped deeper and now Rosicky is playing behind Van Persie. Song puts in a crisp tackle on Pinzi and is booked. That was a very modern yellow card; in other words, it was a load of horse pucky.

49 min "Di Natale looks like a good player," says Niall Mullen, "but let's reserve judgement until he moves to England and scores against a newly promoted side."

51 min Udinese have the radge on here, big time. Neuton went down in the Arsenal half after what was a fair tackle from Rosicky. The referee let Arsenal play on, which they did, even when Neuton stayed down. When the ball eventually went dead after a foul from Armero on Jenkinson, Udinese went mildly ballistic – particularly Agyemang-Badu, who started shoving people. He wasn't booked but Isla was.

52 min After 90 seconds of nonsense, the free kick was whipped in beautifully from the right by Van Persie. It was crying out for a slap of heid on leather, but no Arsenal player could get there.

53 min Walcott spins smoothly around Ekstrand, darts forward and shoots low across goal from 25 yards. Handanovic plunges to his left to make a comfortable save.

GOAL! Udinese 1-1 Arsenal (Van Persie 54) Robin van Persie scores a goal of monstrous importance. Gervinho did brilliantly on the left of the box, teasing and then beating Benatia before cutting the ball back for Van Persie to sweep in from six yards at the near post.

56 min So now Udinese need two goals. Agyemang-Badu tries to get one from 25 yards but his dipping shot is too high.

PENALTY TO UDINESE I have no idea what has happened here. Di Natale's outswinging corner from the right was flicked on at the near post and flashed across the face of the area. At that point it was cleared, but then the referee gave a penalty and booked Vermaelen. It was for handball, I suspect, but it seems really harsh.

WHAT A SAVE FROM SZCZESNY! Di Natale hammers the ball high towards the left corner, and Szczesny flies to his right to make an awesome save. It was almost over him as he dived, but he thrust up his right hand and had enough strength in it to get the ball up and over the bar. That's one of the better penalty saves you'll see.

62 min Ramsey falls over in the box after a challenge from an Udinese player; I'm not sure who it was. The defender got the ball and then tripped Ramsey up; you could argue that, by the time he tripped Ramsey up, it was a different phase of play, but Arsenal barely appealed. I think that might have been a penalty.

63 min Diego Fabbrini replaces Giampiero Pinzi for Udinese. They haven't been at the races since the penalty miss; it's important they keep it at 1-1 and then hit Arsenal for the last 20 minutes. With the humidity, they could still win this late in the day.

66 min At the moment Arsenal are really comfortable, but you know how these games work: the team who need two goals score one with about 10 minutes to go, and then everyone ages 10 years in the last 10 minutes.

67 min The increasingly impressive Gervinho wriggles neatly away from one challenge 35 yards from goal, runs to the edge of the box and hits a shot that is deflected straight at Handanovic.

GOAL! Udinese 1-2 Arsenal (Walcott 69) Arsenal are through to the Champions League group stage. Theo Walcott plays a superb one-two on the halfway line with Sagna before outpacing Benatia and angling towards goal. He gets into the box, draws Handanovic and sweeps the ball expertly in at the near post. That's a lovely goal.

72 min Neuton eases a snide elbow into the face of Walcott off the ball. It wasn't a full elbow, just a tap, but it should have been a red card and a penalty. None of the 97 matchday officials saw it, however, so it was neither. The only man who was punished was Sagna; he was booked, I think for protesting.

74 min Benatia fouls Walcott, and for some reason both men are booked. That brings to mind Rudi Voller's treatment at Italia 90. Walcott was also booked in the first leg, so he will miss Arsenal's first group game.

75 min Now Jenkinson is booked for kicking the ball away.

76 min "Arsenal are never through," says Hugh Collins. "There is no lead they can't throw away."

77 min Udinese need three goals. It's not going to happen. Arsenal are having most of the ball. They have shown a lot of courage tonight – as has their manager, particularly with his aggressive half-time substitution. I don't know about you, but I'm delighted for him.

78 min "That's a lot more animated than Nasri was in the second half of the season," says Matt Shelton.

79 min Di Natale should have scored then. The excellent Agyemang-Bayu played a classy pass down the side of the box to put Di Natale through on Szczesny, but he snapped his shot back across goal and wide. It was a goalscorer's miss.

81 min "The image of Nasri scoring 'his first goal for City' seem to show him doing it at home against Manchester United," says Robin Hazlehurst. "The fixture list elsewhere on the site shows that Eastlands is next expecting to welcome MUFC on 28 April 2012 in the league, and as the FA Cup doesn't start for Big Clubs until next year, either Citeh are very confident of an early Carling Cup draw against United or they don't actually expect their new player to score for them for a long time yet."

82 min "What's going on?" says Lee Calvert. "Since when were you allowed to go back on the football MBM? Are the other seven people off the rank before you off sick?"

83 min German Denis replaces Mauricio Isla, who played really well in the first half.

84 min Udinese get a free-kick wide on the left. Di Natale tries to surprise Szczesny with a disguised whip towards the near post, and Szczesny does really well to beat it away with most of his body (but not his hands) behind the line. Szczesny has had a brilliant game, and is probably the man of the match along with Agyemang-Badu.

85 min Van Persie showboats needlessly, which forces Udinese to hare round in a funk for a few seconds. Gervinho is replaced by Armand Traore.

87 min Medhi Benatia is stretchered off to be replaced by Giovanni Pasquale.

89 min" The visiting supporters seem to be chanting 'Wojciech Szczesny'," says Lucas LeCours, "which is great to hear." They know that he is, er, a keeper.

90 min There will be three minutes of added time-killing. Andriy Arshavin replaces Theo Walcott, who is rightly booed off for being elbowed in the face.

Full time: Udinese 1-2 Arsenal That's the end of a proud night for a young Arsenal side, and particularly for Arsene Wenger. On ITV, Peter Drury takes about the £25m victory, but this was about so much more than filthy money. Arsenal showed so much character here. Seasons have turned on less; equally, there have been brighter false dawns. Forget the future: for now all connected with Arsenal should revel in a fine victory against slick opposition in an excellent game of football. Thanks for your emails, night.